1. A father (100 kg) and his son (50 kg) go on a hike in the mountains. The father takes 60 minutes to climb the mountain, and the son climbs it in 30 minutes. Which statement is true about their potential energies (PE)?

The father's potential energy is equal to the son's potential energy because they climb the same height.

The father's potential energy is twice the son's potential energy because his mass is twice the son's mass.

The father's potential energy is half the son's potential energy because he takes half the time.

Their potential energies cannot be related to each other because the path traveled is unknown.

A

B

C

D

2. A spring is stretched 0.20 m. The spring constant is 8.0 N/m. How much energy is stored in the spring?

0.16 J

0.32 J

0.80 J

1.6 J

A

B

C

D

3. A spring (k = 5.00 × 103 N/m) is compressed 0.100 m when a 0.500-kg block resting on a frictionless surface is pushed against the spring as shown in the accompanying diagram.

What is the kinetic energy of the block when it is released?

500. J

250. J

50.0 J

25.0 J

A

B

C

D

4. A single force of 45 N was applied to a 15-kg cart starting at rest until the cart reached a speed of 18 m/s. What was the cart's kinetic energy at the end of the acceleration?

270 J

680 J

2,400 J

4,100 J

A

B

C

D

5. A 0.500-kg arrow was shot vertically upward with an initial velocity of 55.0 m/s. What was the arrow's kinetic energy after two seconds of flight?

100. J

310. J

420. J

760. J

A

B

C

D

6. A 0.250-kg ball, initially at rest, is acted on by a net force of 200. N over a distance of 1.00 m. What is the ball's speed after it has traveled 1.00 m?

20.0 m/s

28.0 m/s

40.0 m/s

48.0 m/s

A

B

C

D

7. A 5.00-kg mass starts from rest and slides down a 3.00-m frictionless inclined plane that makes an angle of 30.0° to the horizontal.

What is the kinetic energy of the mass at the bottom of the incline?

73.5 J

110. J

147 J

441 J

A

B

C

D

8. A 0.15-kg ball is traveling at a speed of 20. m/s. How much work must be done on the ball to stop it?

60. J

30. J

3.0 J

1.5 J

A

B

C

D

9. A student pulls a sled across level snow with a force of 225 N with a rope that is 35.0° above the horizontal.

If the sled moved a distance of 65.3 m, how much work did the student accomplish?

1.80 × 103 J

1.20 × 104 J

1.47 × 104 J

8.43 × 104 J

A

B

C

D

10. A box that weighs 72 N is pulled horizontally across the floor by a rope that makes a 25° angle with the floor. A force of 150 N is applied to the rope and the box is moved 12 m.

How much work is done by the 150-N force?

760 J

1,100 J

1,600 J

1,800 J

A

B

C

D

11. A 650.-kg car traveling at 5.00 m/s was stopped by applying the brakes. How much work did the brakes do when stopping the car?

1,630 J

3,250 J

8,130 J

16,300 J

A

B

C

D

12. A 2.0-kg book falls from a 1.5-m high shelf. What will be the velocity of the book as it hits the floor?

5.4 m/s

15 m/s

20. m/s

29 m/s

A

B

C

D

13. A worker carries a 100-N crate horizontally at a constant speed across a 10-m room. How much work is done against gravity by the worker?

0 J

10 J

100 J

1,000 J

A

B

C

D

14. 50. J of work is used to push a 1.8-kg box up an incline at an angle of 15° to the ground.

The box is pushed from rest at the bottom of the incline to rest at the vertical height of 2.4 m. How much work is done against friction?